<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style type="text/css">
			.box{
				width: 100px;
				height: 100px;
				border: 1px solid salmon;
				margin: 30px;
				float: left;
			}
			.active{
				background: yellow;
			}
		</style>
	</head>
	<body>
		<input type="button" name="btn" id="btn" value="删除元素" />
		<div class="box"></div>
		<div class="box"></div>
		<div class="box"></div>
	</body>
</html>
<script src="js/jquery-1.3.1.js" type="text/javascript" charset="utf-8"></script>
<script type="text/javascript">
	$(function(){
		$(".box").click(function(){
			$(this).addClass("active");
		})
		$("#btn").click(function(){
			$(".box").removeClass("active");
		})
	})
</script>